Signs will be put up on Dawson Street in Dublin asking cyclists to dismount instead of divert.
The new Luas Cross city line opens this weekend, and there are concerns that bicycle wheels could get caught in track grooves.
A proposal to install rubber inserts that could be depressed by tram wheels but not bicycle wheels was rejected due to cost concerns.
The National Transport Authority was refused permission to ban bicycles from the area.
Ciaran Ryan from the Dublin Cycling Campaign said that it is going to be very dangerous.
"Specifically from Dawson Street down to College Green, across O'Connell Bridge and also O'Connell Street, there are lots of places there where cyclist may just fall off their bike without any warning because of the Luas tracks," he said.
"What we're asking is that drivers keep well back from people on bikes."